The *myc* gene family plays a critical role in both normal and cancer cell biology, regulating a wide range of cellular processes such as proliferation, growth, apoptosis, energy metabolism, and differentiation. Myc proteins, which heterodimerize with Max and bind to E-box sequences, act as transcription factors that can both activate and repress gene expression. Recent studies have revealed that Myc has a much broader regulatory effect than previously thought, influencing thousands of genes and playing a key role in stem cell maintenance and cancer development. Myc's ability to modulate gene expression is not limited to its direct interaction with DNA but also involves interactions with other transcription factors and coactivators, which can influence chromatin structure and transcriptional activity. Myc's function is also regulated by its degradation, which is controlled by ubiquitin ligases such as Fbw7 and Skp2. The dynamic nature of Myc, with its rapid turnover and interactions with various coregulators, allows it to finely tune cellular processes and respond to changing environmental signals. In the context of stem cells, Myc is essential for maintaining stemness and preventing premature differentiation, but its deregulation can lead to uncontrolled cell proliferation and tumorigenesis. Myc's role in cancer is further highlighted by its ability to promote the formation of cancer-initiating cells that retain developmental plasticity. Understanding Myc's complex regulatory mechanisms and its interactions with other cellular components is crucial for developing targeted therapies for cancers driven by Myc overexpression.The *myc* gene family plays a critical role in both normal and cancer cell biology, regulating a wide range of cellular processes such as proliferation, growth, apoptosis, energy metabolism, and differentiation. Myc proteins, which heterodimerize with Max and bind to E-box sequences, act as transcription factors that can both activate and repress gene expression. Recent studies have revealed that Myc has a much broader regulatory effect than previously thought, influencing thousands of genes and playing a key role in stem cell maintenance and cancer development. Myc's ability to modulate gene expression is not limited to its direct interaction with DNA but also involves interactions with other transcription factors and coactivators, which can influence chromatin structure and transcriptional activity. Myc's function is also regulated by its degradation, which is controlled by ubiquitin ligases such as Fbw7 and Skp2. The dynamic nature of Myc, with its rapid turnover and interactions with various coregulators, allows it to finely tune cellular processes and respond to changing environmental signals. In the context of stem cells, Myc is essential for maintaining stemness and preventing premature differentiation, but its deregulation can lead to uncontrolled cell proliferation and tumorigenesis. Myc's role in cancer is further highlighted by its ability to promote the formation of cancer-initiating cells that retain developmental plasticity. Understanding Myc's complex regulatory mechanisms and its interactions with other cellular components is crucial for developing targeted therapies for cancers driven by Myc overexpression.